The King of Ruin
by Mr Always-Bad-Grammar
Summary: Satanael, once the Angel of Order, now becomes Satan, the King of Ruin, and swears revenge on those that have wronged him. AU!DxD with many changes. Features elements from various popular video games and some anime/mangas. Rated T for violence and mild curses. VERY powerful yet very restrained OC. Pairings undecided, don't let Satanael's relationship with Gabriel fool you!
1. Chapter 1

Note: There will be some elements from various popular games but not enough to be considered crossover(s), cameos at best. Set in DxD so my OC must have a harem but whether he genuinely loves them or not is debatable.

* * *

~Prologue, First Half~

Satanael was a middle-class Angel assigned to be in Archangel Gabriel's personal Legion. He was a very hardworking Angel to repay the Almighty for his kindness and the Archangel herself for her acceptance him into the Legion. Due to his below average physical health, he was ranked 987th of 1000 Angels and could only do mediocre tasks such as bring weapons for the higher ranks or do errands for Gabriel but he was happy with it. Even the Lady herself had been calling him for such things lately so he knew that he would be promoted soon and Satanael could finally purge the demons in the name of his Lady and God.

Satanael disgusted at himself for ever harboring feelings toward Lady Gabriel other than respect and loyalty. He secretly consulted this matter with the so-called Master of Love that he heard from the gossiping fellows, Samael. The suspicious-looking Archangel explained to him that the feeling was called 'love' and briefed him with a sizable information about such emotion. Satanael almost yelled out that doing such thing was a great sin and guaranteed to 'Fall'.

"You will be fine. No one gets fallen just by confessing his love, my boy Satanael. Just look at your fellow brothers."

Satanel frowned but nodded at his words nonetheless.

"Don't worry my boy. I will personally back you up." Samael used his enhanced vision to search for something. He smiled. "Gabriel is currently in the Sanctum with his Lordship, discussing. Wait until the Lord is gone and do it. I will follow you right away."

Satanael bowed at the Archangel and made his way. When he was out of earshot, Samael let out a malicious grin.

"…My Lady."

"Ah it's you, Satanael. What's the matter?" Gabriel beamed the usual kind smile of hers to Satanael. The latter felt like his heart skip a beat in that moment before speaking with all his courage.

"It is considered a sin to do this but." His eyes closed shut. "I love you, my lady Gabriel."

The Archangel gasped in surprise and embarrassment at the confession. She could not find any words to say. Satanael continued.

"It is perfectly fine to turn me down, my Lady. I am already prepared my heart for it and I am willing to take any punishments –"

"And that's what I am about to do right now."

Samael appeared with a group of guards and said. Behind him was the God Almighty himself and a furious Raphael drawing the Sword of Judgment. Both Satanael and Gabriel stared at them dumbfounded before the guards moved to apprehend the former and Raphael stood before the latter protectively.

"Satanael, how could you plot to, pardon my language, _rape_ your Ladyship and make her Fall with you?" Samael asked with a mock disapproving expression. The Angel in question was confused.

"But my Lord, I don't know what 'rape' is. How can I do such thing to lady Gabriel?" He inquired with a straight face. Raphael almost murdered him before his Father stopped him with a look.

"Don't you dare joke with me, scum!" Raphael snarled. Samael faked a frown at his brother while walking toward Satanael and whispering something to him. His eyes widened in shock as he forced himself to kneel despite the restrains from the guards.

"My Lord, I did not attempt to do such blasphemous and disgusting action towards Lady Gabriel! I have served her with my utmost dedication and not once have I harbored such thought!"

"My son, I am very disappointed. Attempting to violate my daughter is already grievous and now lies? You have sunken too much now Satanael. Samael, if you may."

"Understood, Father." Samael showed a projection of Satanael's earlier meeting with the Archangel but something was _very_ wrong. He was spouting words about his desire to rape Gabriel and Samael was trying to advise him against it but he didn't listen and storm away. He was silent, trying to digest the screen before realization dawned on his face. He lunged at Samael with a roar.

"HOW DARE YOU SET ME UP?!"

"Tsk tsk, how the noble and ever diligent Satanael has fallen." Samael sighed. "Do you see that, Father? This proves that even the most trusted and considered to be incorruptible can be corrupted. We must act quickly or else it would be too late. And Sister."

He turned to Gabriel. "Thank you for your cooperation. Without you putting a façade, we could not catch this filth easily."

"W-What are you saying –"

"Don't tell me, your Ladyship conspired this with him too?!" Satanael looked at Gabriel with horror in his eyes, despite the latter trying to explain that she did not. God, at this moment, knew that something was wrong. He knew that Satanael, who was known as the Angel of Order and Loyalty, would not commit such heresy but without clear proves, he could not say anything. While Raphael demanded to let him handle the execution, Samael suggested the most merciful solution: cast him down to the mortal world.

"Hahaha…"

"What now, scum?!" Raphael shouted.

"HAHAHAHAHA! I understand it now!" Satanael suddenly yelled out with a maniac glee. "I have been a toy for you all to play with from the beginning. A weak but willing toy."

He dryly laughed. "Born without the necessary health to do his duty. Angel of Order doing errands like a _fucking_ slave? Hah! You can no longer deceive me, O _False_ God."

"Why you?!"

"You act like an innocent girl but in reality, you are a **bitch in sheep's clothing**, my _Lady_." Gabriel was almost to her knees at the accusation.

"That's it, I will tear your body apart heretic!"

"No need! I will do it myself." Satanael reached his wings and started _pulling_. The sound of flesh and bones being tore from his back sickened those present, even Samael. Despite the immense pain, he did not scream. Instead, his smirk kept growing until it became a slasher smile. The process was finished and he threw the bloodied wings, what defined an Angel, to the feet of God.

"I won't allow myself to be tainted with black. But I allow hatred and malice fill my heart and soul!"

"Stop, Satanael! I beg you, any more and you can no longer walk on Heaven again!"

"Shut you trap, Gabriel the Bitch!" Satanael snarled. He was one inch to the Pit, door to the Underworld. "Mark my words: I will train my body and then gather an army, a Legion of my own, to level this disgusting place before killing you all. Starting with you, dear _Father_."

"Satanael, I cannot tolerate your words anymore. I banish you to the Pandemonium and forever get trapped in there!"

"So be it! And I shall be Satanael no more. I am _Satan_, and I shall get my revenge no matter how long it takes!" He yelled to the sky before taking a step and falling into the dark pitch depth below.

* * *

For a hundred years, Satan had pushed his body to limit and eventually became powerful, so powerful that he wiped out the devils with one flick of his hand. He met a demoness called Leviathan after saving her from an Angel patrol and she swore her loyalty to him despite knowing his true identity thanks to her power. A master of mind and ice magic she proclaimed and he tested them himself. Satan was pleased.

Satan and Leviathan gathered up a small warband to conquer the other warlords and assimilated their armies. Soon, he recruited the brilliant tactician Beelzebub and the master of stealth Asmodeus. The latter also carried the job to recruit more Devils into their cause.

A short time later, Underworld was 90% under Satan's leadership. But he did not satisfy. Satan needed more than just his current power in order to slay the wrenched God and his children. So he began to seek out those who possessed extraordinary abilities and defeat them to gain their powers. Eventually, he gained the total of twenty different abilities that would help him slay the Archangel of Might during his arrival at Underworld to search for Satan, or rather, Satanael. The essence of Zeruel was then absorbed into his blade and one swing of it almost split the barrier between realms. Like Satan would need it though since with his current abilities, he could kill the highest of the Archangels and at least incapacitate God easily but he always brought it with him all the time.

…

Satan stared dumbfounded at Helel, his eldest brother, or what Helel had become. Alongside him was a very large number of Blackened Angels or as Asmodeus said, Fallen Angels. Much to his delight, Samael was among them. But personal vendetta later, he had to ask Helel.

"Brother, what sin did you commit to get casted down to the Underworld?"

"He asked us to bow to _them_." Helel spat out venomously. "We, the Angels, have to bow to monkeys? Ridiculous!"

"Ah I see." Satan chuckled while taking a good look at the Black Angels in the front row. "Azazel, what could possibly make a brilliant individual like you fall? Certainly you don't care about His decisions and all."

"Um, well, that is a personal question that I would like to answer in an appropriate time." Azazel said meekly, causing his two subordinates to laugh slightly. Satan somehow understood the undertone and nodded wholeheartedly.

"Oh well, what is done is done. Come, let us find a suitable place for you all to stay!" Satan said with a smile. He turned to his newly found general, Lucifer. "I can trust you with this task, Lucifer?"

"With my pleasure, my lord."

"Good. Now, my brothers, let us head toward my castle. You all must be hungry after all!"

* * *

I won't be focusing in the Great War much since my current idea only covers up to two chapters at best. Satanael's shift of personality can be explained by exposing too long for a certain magic and combining with his hatred, it is miracle that he does not go full insane.

Stay tuned for the second and the final part of the Prologue guys!


	2. Chapter 2

Note: Satanael's original title is Seraphim of Order, after demotion, Angel of Order. Satan's title is King of Ruin, Destruction and Despair. His more common ones are Overlord of Underworld, Unmatched King of Hell, Emperor of Pandemonium or just plain King of Hell.

* * *

~Prologue, Second Half~

Lucifer found a secluded and mountainous area for the Fallen Angels. His Lord suggested a closer one so that he could visit his brothers frequently but the majority of his generals and troops still hated the Angels, regardless of their current state. Helel let his subordinate Azazel handle the construction of their new base while the Morning Star stayed to offer an alliance with the Devils. Satan wholeheartedly agreed as if it was a norm. But then his face crept a maniac glee, the same one Helel had witnessed at the moment that Satanael 'died' long ago.

"Leave Samael here to me. I have _so _many things to do with him."

"Samael is punished for the trickery he has pulled for millennia, including your Fall. Father sent Zeruel to bring you back, He even erased your sentence –"

"NEVER MENTION THAT FALSE GOD IN MY FACE AGAIN!" Satan roared as the glasses in the hall shattered. The Fellsword of Damnation almost cleaved the building in perfectly clean half if Beelzebub didn't snatch it from his lord. Satan snarled at his general when Leviathan used her magic to ease his mind.

"Ah yes yes…" Satan said to himself with a small smile as he sat down, hands waving to cast a spell that repaired the damage he had caused earlier. Helel was unnerved by the hatred he saw in his brother's heart when he tried to take a peek inside Satan's consciousness. No wonder he became so powerful right now, his rage fueled his willpower to overcome his weakness.

"In second thought, I have a better idea. How about this…" Helel whispered to Satan's ear and the latter chuckled.

"Good good, it sounds good. As much as I want to chew his body to the last bone, I guess my appetite must wait. As of that matter, I'm afraid that we have to postpone that until your army is well-prepared. For now, we the Devils will keep raiding on every Heaven outpost we found to reduce their troops on both Underworld and the land of mortals."

Satan snapped his fingers as Beelzebub brought out a large and detailed map on the table. There were many 'X' marks and various symbols on it. He frowned and turned to his general.

"How many times did I have to remind you to replace this piece of paper with a new one with only a black mark on each of the conquered areas?!"

"B-But this is the only completed map we ever have in the Underworld, at least until now!"

"…Seriously? Asmodeus, send Corvus and his Company, alongside the other fastest units available to spread out and try to memorize every single area in our sector, excluding the ones that too secluded or within the territory of the Fallen Angels." He turned to Helel. "Brother, tell Azazel to meet up with me as soon as possible. We will need his legion's help to expand the map too."

"That I can arrange, Satanael." Helel nodded curtly while Asmodeus excused himself to meet his underlings.

"Good. Well then, we warp this up for now. Lucifer, lead my brother to the region that you chose for his army. Remember to watch out for those chickens, lately they have Cherudim-class among them. You cannot handle ten or more of them easily."

"Understood. Lord Helel, if you may."

Helel said goodbye to Satan and his generals before following. Satan then frowned at the mess of a map. A question mark was placed on the spacious plain area with the word 'Bael' displayed near it. The Bael was a proud and arrogant clan, even after he killed their leader due to their flat-out insulting his general, Levithan, for her failure of a clan leader. He didn't divert much into each of his subordinate's background, as long as they were loyal to him, he was fine with them all.

"It is the Bael, isn't it my lord?" Leviathan inquired with a worried look. Satan nodded slightly as he massaged his temple.

"They are the most stubborn bunch I have ever met since my arrival at this realm. Granted that I can easily wipe them out of the earth for their attitudes toward you," Leviathan blushed heavily. "but that would demoralize our troops and then lead to unfavorable scenario. After all, the Bael is the largest warlord until my rise. Beelzebub, do you have any suggestion? The Armageddon is near, but we can't even unite our own people then how can we stand against those pretentious bastards?"

The man in question started calculating the possibilities. Leaving the tactician, Satan summoned a portal leading to his personal training ground. Today, he must master the Art of Time from the book that he borrowed from the Agares clan. Two hours later, Beelzebub ran so fast as if his life was on the thread to Satan's chamber, right during his first successful cast of the Time Stop ability.

"My lord! The Bael, they – Oh shit!"

"Beelzebub, you foooooooooooool –"

Needless to say, the guards were panic to find the duo frozen mid-air with terror in their faces. Leviathan had to call for Lord Agares to unfreeze them.

"Ahem…" Leviathan coughed at the King of Ruin who was busy kicking his subordinate's butt, literally, for the accident earlier. The representative from the Bael clan tried his best not to laugh.

"You idiot! Don't your parents teach you how to knock the door?!"

"I-I am very sorry, my lord! It was urgent so I – Ouch, forgive me my lord!"

At that moment, Azazel happened to arrive as well. He was mortified to see a once the Angel of Order now was hitting his underling in a serious yet comical manner. Satan seemed to recognize the presence of his brother. He promptly delivered one last kick to Beelzebub and then regained his composure like nothing had happened.

"Beelzebub, pick your ass up and deal with the Bael man for the time being, my meeting with brother Azazel is utmost personal."

"A-At once, my lord! Ouch…"

"Good. Come, my brother. We will speak in my room."

…

"Brother, why so soon? I thought the construction should be taking at least one week to finish the basic structure, especially in that kind of terrain."

"My dear brother, you vastly underestimated my crew. Did you forget that my legion is among the best in this field back in Heaven." Azazel smugly said.

"Hahaha, indeed. But into the business, why the hell are you even Fallen, brother Azazel? You are not the type to sink into the sinful desires nor get into a mess like I did. The False God even granted you the privilege to access the most forbidden scriptures for inspiration!"

"Um, well, I was caught red-handed while doing ecchi with a mortal girl…"

"Ecchi?"

"You know, sex stuff. And I am sorry to say this but I have always had those perverted thoughts in my head and when I met that girl, I could not resist and a voice in my heart told me to go for it and…I did it."

Satan was speechless and was doing some incomprehensible actions to describe his thoughts. Azazel knew of Satanael's great respect to his fellow brother, except Samael of course, and now one of them got fallen for a trivial reason like that. Then he laughed.

"Good! You have done a great job!"

"What are you saying brother?"

"You follow what your heart tells, that is freedom. The False God keeps suppressing our true selves so that we are just puppets for him to play and toy with! A dog that does his biddings!" And then he stopped laughing. "Unlike me, I did my task just like my heart told me to, and then I got manipulated and then thrown away like a broken doll! From the beginning, I knew that something was very wrong with my body. Even a low-class can beat me in combat, you heard it, a LOW-LEVEL! Defeated! A MID-LEVEL!"

Azazel nodded grimly. It was a secret among the high-ranking Angels that Satanael was God's second son after Helel, but for whatever reasons his memories was wiped and demoted from Seraphim, the highest position that Helel and Metatron belonged to, to a Mid-Level Angel with majority of his strength sealed. God created Helel to lead the Angels while Satanael was his Sword to strike down enemies. Azazel knew for a fact that the seal had not been broken at all and Satanael was this strong already. Ooh Michael and his siblings would not like this when he set his foots once again in Heaven. Azazel waited until Satan ended his rant and calmed down to speak.

"Oh well, what is done is done. While I don't like fighting much, I will surely lend a hand in the Armageddon to you, brother." He remembered seeing Leviathan standing with Satan. A fine lady she was. Azazel decided to tease Satan.

"You know, brother, you did a good job at forgetting Gabriel and went for that female subordinate of yours. I feel so proud of you!"

"Ah, that." Satan dryly laughed. "I lost my ability to love not too long ago. When I fell to this place, I was weak. I was chased around by the weakest of the Devils. I was powerless and I loathed the weakness that got me in this situation. So I let hatred consumed my heart, and let it eat away the useless emotion that called 'Love'. I am well aware of the feelings Leviathan has for me but it is no use, I am currently incapable of feeling 'love'."

"Oh you poor thing…" Azazel muttered with a sad smile as he pitied Gabriel and prayed that once Satan entered Heaven, he would not murder her in cold blood.

A few serious talks later and Azazel tried to lighten the atmosphere by reminding Satan of the fun memories and his misadventures in the mortal world. The Overlord laughed lightheartedly and called the servants to bring out wines and foods until Leviathan 'politely' admonished him that there was still the representative of the Bael clan waiting for him. Satan blinked his eyes twice before coughing.

"Ahem, well brother, it seems that I have other matters to attend. Please make yourself at home. I will be right back."

* * *

Turned out the straight face that old man Bael had made back then was a front to save face for the clan since Satan effortlessly tanked the Power of Destruction blast from Lord Bael and then obliterated him completely with a gravitational beam that Satan dubbed 'Graviton Blaster', which eventually became the Overlord of Hell's signature attack along with the gigantic magic glyph that rained down destructive beams called Raintive Orion, although he knew a vast amount of spells and attacks alike.

"An alliance without any terms? Do you take me a fool?"

"Technically there is none, but in my understanding of his nature, lord Zekram Bael wants a high seat in the government in return."

Asmodeus, who had just returned from the assignment, commented, almost making the representative's heart stop beating due to how accurate it was. Satan smirked devilishly as he opened his palm to reveal a pitch black energy sphere.

"Mr. Representative, do you know what this is?"

"S-Sir, it's the infamous Graviton Blaster. Please don't kill me!"

"Oh no, I won't. I am rather pleased with your presence here, bringing the news to me. Otherwise, when I am out with my army, who knows what that old geezer is gonna do. No, Mr. Representative, _this _is for Zekram Bael himself. I have deployed a sizable orbital formation of Graviton Spheres above the territory of the Bael. One snap and the area will become a wasteland along with your master. Now, the question is," He stared into the poor Devil's eyes with a crazed glee. "Will you spit out everything I need to know, or I may kill you as well."

And the Devil said everything. Apparently Zekram would, indeed, use Satan's absence during the upcoming Armageddon to usurp his rule and if he survived, Zekram would assassinate him. Lucifer was furious and demanded to lead a legion to deliver judgment upon Bael but Satan waved it off with a lax smile. He sent a servant to escort the Representative and then he revealed his agenda.

"I have anticipated this from the beginning. I am no pureblood Devil by all means, yet I am ruling the entire Underworld, which is an eyesore to a proud pureblood like Zekram Bael. Countermeasures have been made so Lucifer, you can go back to your daily duty. No need to think so much."

"I, I… Understood, my lord." Lucifer reluctantly obeyed and left the hall. Azazel chose this moment to enter.

"Brother, have you gotten fed of foods and drinks already?"

"Nah, they are great but I'm afraid that I still have my own duty to attend."

Satan laughed as he patted his brother's back affectionately. He personally escorted the Fallen Angel to the entrance.

"Brother, send Baraqiel and Shemyaza my regards. Armageddon is still far from now so just relax and enjoy your new home. I will visit you as soon as I can."

* * *

Time passed as the Fallen Angels adapted to the Underworld and joined hands with the Devils to influence the mortal worlds with their devious ideals. Satan, however, banned his people from having the humans worship him, as he loathed any prayers that the 'children of God' made for him.

Back in Heaven, Gabriel had been guarded closely to prevent her from going to the Underworld to meet Satanael but one of her gifted powers from God showed a vision where the forces of Devils, Fallen Angels and Angels fought against each other and then Satanael was the one who murdered his Father, ending the war. She warned God of this and while occupied by a different vision, He still amassed his army, waiting for that day.

…

Helel had a similar vision but it showed his death at Michael's hand. His visions never lied. Helel consulted this with his closest subordinates and Satanael, of course.

"Can't it be changed? No way around?" Satanael, his most trusted brother even after he had become the King of Ruin, asked desperately. Azazel shook his head sadly. Helel managed to smile.

"I am going to die, true, but I want to make a glory last stand against Father and our former brethren. All of you, except Azazel and Satanael, leave us be." The other Fallen Angels complied and exited the giant hall. After making sure that there was no one eavesdropping, Helel confessed one more vision.

"During the Armageddon, some of my subordinates who still have the hatred toward Devils will lead a rebellion and turn on your army, Satanael."

"…Any notable name?"

"Kokabiel is among them. But do not confront him, not this soon. The vision showed me that he will be slain by the Red Dragon Emperor with the help of the White Dragon Emperor under the guidance of the King of Ruin, meaning you my brother. Azazel, your task is to minimize the damage as much as you can but still have to let the rebellion happen."

"I respect you, brother Helel, but I cannot fathom seeing my people getting slaughtered by some fools that you cannot control." Satanael scowled.

"I perfectly understand that, Satanael. But you must understand, there is an extra player in our world and they are watching us fight against each other like some sort of an entertainment. In the era where Kokabiel will be slayed, that faction will reveal themselves and you will destroy them with Satanael in my stead, Azazel."

The Black Angel in question was confused. Satanael sighed. "It means brother Helel makes you the next leader of the Grigori, Azazel."

"B-But Helel, I cannot accept such offer! I don't have the natural ability to lead like you and Satanael!"

"You can do it, Azazel. It would be difficult, but I believe under your leadership, the Grigori will become a powerful faction that can rival Heaven and even Hell." This made Satan snort.

"Is that a challenge, brother?"

"It definitely is." Three of them laughed, just like the old times.

* * *

And then, Armageddon finally came.

Satan mercilessly rained down on the helpless Angels who were unfortunate to get trapped within the white glyph of Raintive Orion, they even didn't get to scream as the beams vaporized their bodies completely. His army advanced with the support of the Fallen Angels from above and soon, they arrived at the Great Entrance. Greeting them was a large legion with Raphael, Michael, Uriel, Metatron and the other high-ranking Archangels.

"You will step no more into the sacred sanctum of God!" Raphael declared as he drew his Sword of Judgment.

"Satanael, how dare you show up here after murdering Zeruel?! Does your heresy know no bounds?!" Uriel shouted with anger in his voice. Satan replied was a maniac laughter that silenced the heated atmosphere. And then he snarled.

"HERESY?! IS IT A HERESY TO BE BORN WITH SO MUCH POWER THAT THE FALSE GOD HAS TO SEAL IT AWAY SO THAT I CANNOT USURP HIM?! IS IT A HERESY TO LOVE AND THEN GOT SCREWED LIKE A BROKEN DOLL?! IS IT A HERESY WHEN YOU HAVE TO SUPPRESS YOUR DESIRE JUST TO OBEY THE FALSE GOD LIKE A FUCKING PUPPET?!" Azazel nodded at the last question.

"It is our duty to obey Father! And don't you dare speak that name again!" Sandalphon yelled.

"I DARE! AND NOW, THE TYRANNICAL RULE OF THE FALSE GOD SHALL END HERE! MY ARMY, CHARGE! DESTROY EVERYTHING ON YOUR PATH –"

"Please stop this, Satanael! A gentle soul like you is not like this!" Gabriel pleaded desperately. Satan blinked at her while in the background, Leviathan muttered something between 'That bitch' and 'A whore'. And he laughed again.

"Oh damn, it is so hilarious!" The maniacal glee appeared again. "DO YOU THINK YOU HAVE THE RIGHT TO SAY THAT, HARLOT?! I WONDER WHO WAS YOUR NEXT VICTIM AFTER ME, IS IT REMIEL? SARIEL? OR EVEN BETTER, METATRON? NO MATTER!" He signaled Leviathan to come forward. "MY GENERAL LEVIATHAN WILL HAVE THE HONOR TO MANGLE YOU AND THEN YOUR CORPSE WILL BE A GREAT EXAMPLE FOR THE OTHER HARLOTS OUT THERE!"

Gabriel was too hurt to continue as she collapsed with her subordinates carrying her into the inner sanctum to recover.

"You will pay greatly for that, scum. All troops…!"

"Leviathan, remember not to kill her. Her survival is crucial in the prophecy, no matter how much you hate you, do _not_ kill her. Understand?"

"…Crystal." Leviathan bit her lip to prevent her from cursing Gabriel before her lord.

"Good. Brother Helel, let's begin the feast. CHARGE!"

…

Satan brought his Fellsword upon Remiel and cleaved the Archangel in half before blasting away his remained warriors with the Graviton Blaster. He was close to the Seventh Heaven and he could feel the immense aura of God behind the gate. A heart-crushing feeling flashed across his head as Helel felt before Michael, just like in the vision. Satan let one single tear fall on his cheek and destroyed the gate with a kick.

"So you have returned, my son."

"Oh spare your honey words, _father_. I have come for your head, and the freedom of every creature – What…are you…?!"

Before him was a rotting Bible God with numerous runes, implying curses, on His holy body. Satan felt a surge of long-forgotten emotion in his heart as he made a run to his Father.

"What… How… When?!"

"Trihexa tried to materialize into the Realspace. I managed to put thousands of seals on it but it also managed to put countless cursed on me…"

"Stop talking! I will find Michael!"

"No… He will certainly kill you in sight. Listen here, Satanael, you must end my life or else the curses will take over me and force me to open the seals on the 666. It is also your intention from the beginning, correct?"

"But…But there is no glory in this! How can I face Helel if I do this?!" Satan shouted.

"Ah, Helel. He foresaw this and decided to take things into his hands by trying to defeat the Beast by himself, but got grievous injures in the result. And it was my own fault that drove him to Fall." Blood started dripping down from God's mouth as his body reached its critical point of toleration. Satan, no, _Satanael_ gritted his teeth in anger and hopelessness as he reached his Fellsword of Damnation.

"Yes. Put an end to this miserable old man. Satanael, you may know that Samael was the one causing that event but I have a major fault as well…"

"Stop talking! Just…stop…" Tears flowing freely on his face as Satanael stood up, poured energy into the blade and held it above the heart position on the God. The latter closed his eyes, preparing to depart from this world but without saying his last.

"When things die down, meet Michael and he will show you the reason why I did those horrible things to you. And Satanael? I am proud of you, my son."

"AAAAAAAAARGH!" The Fellsword hit its target and the divine light of the Seventh Heaven dimmed down and then everything went dark.

* * *

The casualties from all sides were big. Despite Azazel's intervention, the rebelled Fallen Angels still managed to take many lives of their former allies and lost as many. All Four Generals of Satan were among the dead. Beelzebub fell to Raphael's blade, Asmodeus was stabbed to death by Sandalphon, Lucifer put a good fight against Metatron before succumbing to his wounds and Leviathan was the one to lose the final clash against Gabriel. Although the news of Satan slaying God was spread as fast as light could travel, the King of Ruin himself was also declared KIA. Therefore, no faction won in Armageddon. The survived generals of all sides signed a temporary ceasefire to avoid further bloodshed. Satan declared that once he was dead, his Four Generals of Satan would become the Four Great Satans and rule the Underworld altogether. The so-called Kings and Queen managed to keep Hell from falling to the invading Fallen Angels until the Civil War broke out. The Old-Satan Faction lost to the Resistance and a new generation of Four Great Satans came to rule the Underworld, promising to make it great like it had been under Satan's rule long time ago.

There was a peace, not technically a peace but still a peace, for a long time on the world. Nowadays, in Kuoh, a man with jet black hair, blood-red eyes and six demonic yet angelic wings descended on the local park. There was a Fallen Angel in the area who happened to see. He managed to utter one word and one sentence when he was obliterated by a gravitational blast.

"SATAN! SATAN IS BACK!"

* * *

So the Prologue is finally finished. Chapter 1 will be told in Satan(ael)'s FOV of course, but he won't steal the spotlight from the DxD cast, at least not the entire spotlight. He does have a Peerage but it won't function like a Peerage. Stay tuned!


	3. Chapter 3

Satanael does know of the Peerage System, as well as its Heaven counterpart, but he chooses not to use, at least not now, due to how unstable it is. How can a weakling overpower a much more powerful opponent with the help of a chess piece instead of striving to become stronger himself?

A side note, no, God didn't unseal Satanael and he didn't even bother to find a way since it functions entirely different to the most common and obscure types of seal.

* * *

~Chapter 1~

There were several centuries-old records kept in every realm depicting a handsome young man in his twenties with blood-red yet not vampiric eyes, a jet black hair with small but noticeable golden trims and on his back was three pairs of both demonic and angelic wings. In his possession was an exotic but powerful sword that was reported to be capable to destroy the world and a set of armor that was so tough that the most powerful spells could not leave a dent. Various sightings of the man thorough the span of history implied that he had a hand in many historical events. It was him who averted the tragedy that would have become the tale of Brynhildr and Sigurd; it was also him who rescued and prevented the priestess Medusa from becoming the monstrosity Gorgon; the hatred of Adolf Hitler toward the Jews was also his doing. These were just some notable ones among the machinations that this mysterious young man caused.

There was a short yet absolute rule in all worlds: do not engage in combat with the Alpha Legion. No one knew of this Unit, except that they had been once the personal guards of the King of Ruin when he was alive. Their number was greatly reduced but their reputation of ruthlessness and brutally executed operations inflicted fear to everybody. Very few individuals that had met this Legion recognized the Lord of Locusts Apollyon, famed Dragonslayer Sigurd, Raven Lord Corvux Corax and even the Wolf of Darkness Cerberius among the only ten members. Famous Librarian Lorgar Aurelian of the Church, born 1578 and died 1623, wrote in his journal during the last days of his life that during the Battle of Megiddo, he witnessed the very same young man from the old scriptures in the Great Library of the Church giving orders to the dreaded Unit in the three-way fight against both the angels and their human warriors before emerging victorious with little to no casualties. Lorgar was among the POWs and got the precious conversation with the leader of Alpha Legion himself. To his horror, he was the King of Ruin.

Surprisingly, Satan just wanted a small conversation with Lorgar over the topic of belief. The Librarian was surprised at the fact that Satan was a bit disappointed at the depiction of him in the Church. Urged by his curiosity, Lorgar asked many questions about the Heaven and Underworld. Satan answered them all with his genuineness, all of which would later be written in books and distributed widely in the Mortal World. Majority of the Church declared his works heretic but the more level-headed figures found the information massively useful and combined with Lorgar's objective perspective, they were convinced and thus allowed the distribution to continue, though the knowledge about Underworld and its habitants were restricted and only the members of the Church could read them.

* * *

To the citizen of Underworld, Satan was their most beloved king, even above the current rulers. That was the reason when he and the Alpha Legion appeared during the Civil War, both sides wanted his support. Much to the Old-Satan Faction's dismay and rage, he chose the Resistance. The Alpha Legion almost singlehandedly destroyed their army. Despite his best effort, Corax could not capture all the Satans except for Katerea Leviathan.

Katerea was stripped of her robes and was imprisoned in her former chamber. The Emperor of Pandemonium personally visited her, accompanying him was Cerberius and Ludger von Weinberg, his spymaster and expert interrogator. He ordered the two to stay outside to guard while Satan himself would meet the Leviathan. Satan took off the sinister helmet to reveal his ever youthful face to the blushing Katerea. He spent the next two full days to talk and persuade her to abandon the wrong and old ideology of the Old-Satan Faction. It was difficult, especially her hatred toward the current Leviathan, a young and powerful girl from the Sitri Clan. He ordered Ludger to gather as much as possible about this Serafall Sitri.

"I see. No wonder you lost to her, Katerea." Satan said while looking at the documents. "Although you are the direct descendant of Leviathan, this Serafall girl inherits the power to manipulate ice from my general, which really bothers me if the Leviathan back then was actually a Leviathan or just a Sitri taking that name."

"My lord, I have no excuse for this failure but please allow me to fight her again! I will take my rightfully title back –"

"No Katerea, you have a much more important task right now." Satan motioned Corax to present the map of Underworld. "General Corax has confirmed the location of Creuserey, Shalba and Rivezim along with their troops. It seems that Shalba is trying to get in touch with you for obvious reasons. The Raven Lord is jamming the magic signal under my order." He looked at Katerea. "I ask you to put aside your rivalry with Serafall Sitri, as well as the Resistance, to cooperate with them to help me identify your mysterious benefactor. Can you complete the task, Katerea Leviathan?"

"…My lord, that I can accomplish but." She was unusually nervous today, Satan noted. "If I succeed, please include me in your Peerage!"

Now Satan and his present generals were at lost.

"Peerage? What is that? If you mean joining my Legion, you are already in."

"No! I mean, your personal Peerage." Katerea was fidgeting in her seat. "I want to fight alongside you just like the first Leviathan. I want to be your Queen!"

"…I can't comply your request Katerea." Satan shook his head. Katerea looked like her world was collapsing when he made a deadpanned face. "I don't even know what the heck is Peerage, how can I make you my Queen?! And I never have a Queen even back then!"

Katerea almost face-palmed but chose not to as it would be un-ladylike and disrespectful to her king.

"I-I see. If you want, I will explain this wrenched Peerage system to you."

"Not now, let's focus in the current matter first. You will rejoin the other Satans for the time being and report to me any suspicious activities, understand? Furthermore, if you are compromised, crush this pendant. It serves as an emergency warping spell that will teleport you to my location and alert any Alpha Legion companies nearby." He produced a small pendant and gave it to Katerea. The woman gracefully received it and wore it immediately.

"One last question, my lord. What are you going to from now?"

"Ah, that's a good question. I feel it's not the correct time to reveal my presence. I already instructed Apollyon to handle the politics in my stead. In the meantime, I will return to the Mortal World to keep monitoring the Church of Man and try to recruit more exceptional individuals to my Legion. Good people are hard to come by these days, you know."

* * *

-Present-

Rias Gremory and Sona Shitori eyed the new transferred student with interest and suspicion. A ward last night informed them that it detected a Fallen Angel wandering way too close to the human's populated areas and just a minute later, the signal disappeared. It also recorded a high level of energy surge which was on par if not surpassed the Ultimate class. It wouldn't have been too bad if Sona hadn't brought up the fact that even Rias' brother, Sirzechs Gremory the current Lucifer, only got to the Ultimate class in his full power and this one's reading reached the highest peak of Ultimate, a feat that only the original Maous from the Great War area were capable of, excluding Satan himself.

This man, Kagami Nakamura, just happened to arrive at Kuoh an hour prior to that event too, according to her family's agent at the airport. And their readings had already shown astonishing numbers.

"Rias, I think you should not approach him with it." Sona leveled her spectacles and stated. Rias just snorted playfully at her.

"You are just worried about me hogging him first."

"While I would never back down for a challenge like this, he seems to be out of our league." Sona said as if it was a matter of fact. "Not to mention, you already got that Hyoudou boy."

"We Devils are greedy, Sona." Rias chuckled at her rival before retreating to her club's room. The Sitri girl kept pondering over the reports of recently sightings of the Lord of Alpha Legion in Japan. Was it a pure coincidence or something was very wrong since a particular message from Kyoto said about seeing a man with characteristics identical to those of this Kagami Ichirou.

Speaking of the man, he was amused at the conversation between the Devil girls that he ignored a furious Perverted Trio addressing about his good looking and typical fantasies they would boast daily. Twirling his fingers a little, Kagami let out a psychic energy wave that sent those who being supernatural on edge. This should be enough to tell the stalking little girl behind him that he did not want her presence at all.

'So, this is the Red Dragon Emperor brother Helel spoke so highly.' Satanael mused at the flinching Issei Hyoudou, particularly at his left arm. He could see the crimson reptile cowering in fear at his power since in the past, Satan once had an interesting conversation with the Welsh Dragon that left the latter scarred in both body and pride.

'I will see it myself that you are worthy of Helel's expectation.' Kagami turned around and walked off before his grin grew. 'Because otherwise, I will definitely destroy your entire soul for making me waste all these years of waiting.'

Later that day, Kagami was contacted by Ludger. The captain informed that there were commotions in the Church. An extremely valuable object had been stolen by the reportedly Fallen Angels but his spies managed to pry more information and it was rather a dozen of rogue priests, paladins and Templars working with the Grigori to steal this object, an Excalibur.

"_An_?"

"Yes, my lord. Apparently the original Excalibur that Arthur Pendragon possessed was shattered into seven shards and this missing sword is one of them. I can send a brief document of these artifacts to you if you want so."

"Hmm, the timing is too perfect. But to be sure, monitor them for the time being. We cannot act rashly lest our entire effort would be a meaningless. Tell Apollyon to postpone the hunt for those Khaos Brigade insects and gather Sigurd, Corax, Cerberius, Julius and the rest of the captains to gather at Kuoh City as soon as they can. No need to rush but alert them as I said."

"Understood my lord." And Ludger cut off the connection. Kagami knew that their conversation had been eavesdropped from the beginning but well, what's good for being too secrecy? As expected, the Sitri and Gremory heiresses were indeed doing so and they were mortified to hear the dreaded names. The latter reached her brother to inform him of this matter.

The next days were relatively normal for Kagami except the wary eyes of the aforementioned Devils and other creatures in Kuoh Academy. Today was supposed to be Apollyon and Sigurd's arrival, the others were delayed a little but he didn't mind. He was watering the flowers in the school's neat little garden, it reminded him of Beelzebub when he was still alive. His general had a soft spot for plants and as his master, it was his responsibility to honor it. And then he noticed a spike of power in the abandoned building so he abruptly stopped the activity and headed to it, hoping to see something interesting amidst the boring world of humans.

Indeed it was.

"I have told you for a million time already. I will not accept this marriage –"

"Kaichou, we have an intruder." How cruel his luck was. The door snapped open and revealed the short white haired girl from before, he believed she was a youkai or a nekomata judging from her unique Senjutsu, and the ones knowing him reeled back in shock, even a maid he recognized from that time.

"K-Kagami-san, what are you doing here?!"

"Oh, what is this puny human doing here?" A delinquent-looking blonde young man spoke in his arrogant tone. Satan saw red as he lunged forward and delivered a folded hand thrust directly at the blonde brat's heart.

"Do. Not. Equate. Me. With those monkeys!" Kagami snarled as he twisted his hand, which pierced through the man's body to the other side. Despite clouded in rage, he was conscious enough to catch a hand from the maid with inhuman speed, much to her surprise.

"Y-You…bas…tard…"

"Release lord Phenex at once, human!"

The maid demanded before finding her levitated in the air by a hand choking her throat. As if an instinct, his two newly arrived generals warped into the room. Apollyon leveled his dual 'bolt' magnums while Sigurd summoned the shining Bolverk Gram. The tension was so high that the lesser Devils felt like the air was frozen.

It took Rias a lot of efforts to persuade Kagami to release both Riser Phenex, the irritating blonde, and the maid, a Lucifuge if he wasn't wrong. Sigurd immediately berated him for letting his temper get the hold at him. Despite a sizable hole on his chest, Riser managed to laugh. He was greeted by a bolter blowing off his right leg.

"Shut up, worm." Apollyon coldly stated. Grayfia still could not recover from the shock that the Lord of Locusts was here in the same room with her. It was a common knowledge in the Civil War that the Lucifuge was a supporter for the Old-Satan Faction and it costed their clan severely. When the Alpha Legion entered the fray, it was Apollyon who hunted down her entire family and massacred them all except Grayfia and her brother, Euclid as they were defecting from the Faction anyway.

"Do you understand now, my lord? You cannot let the others laugh at us, the Alpha Legion, just because you can't control your anger."

"I know it, alright! Still regret that I didn't blow the brat into the sun though."

"My Lord, that attitude again!"

…

Rias gave Kagami and his subordinates a summary of what happened and the King of Ruin laughed it off. Riser wanted to relent so much but the icy gaze of Sigurd completely froze him.

"I thought it was something interesting, turned out it's a really good joke!"

"Damn it, Kagami. Buchou's life is at stake here!"

"Silence, boy. Don't interrupt my lord." Apollyon said, silencing the boy. Kagami slapped his general's back playfully.

"Nah just let him speak! I find it amusing to see a human-turned Devil boasting about woman's private sections and all. The kid wants to take his master's virginity of all things! Gahahahaha!"

Rias was embarrassed at the statement while Issei huffed his chest with pride. Kiba facepalmed and Koneko just munched her snacks in ignorance. Akeno, in other hand, was eying Kagami with lustful eyes. She had been interested in this new guy lately and his performance today boosted it to new level. Kagami shuddered at the feeling of something is looking at him uncomfortably.

* * *

To regain his authority, Riser summoned his Peerage full of girls and boasted about their strengths. He suggested a Rating Game between him and Rias with the winner would decide the outcome of the arranged marriage, which earned the agreement from Grayfia. They traded glares with each other before Riser left with his Peerage, having agreed on letting Rias ten days to prepare.

"So Apollyon, what is this whole 'Peerage' and 'Rating Game' things again? I didn't pay much attention back when she explained it to us."

"I believe a Peerage is somewhat similar to us Legion, using chest pieces to measure one's ranking. The Devils have been using this for quite a time now to increase their numbers by resurrecting humans with exceptional powers as Devils." This brought a scowl on Kagami's face. "And a Rating Game is a match between two or sometimes multiple Peerages. Think of it like a soccer match."

"I see. Well, this is not our business anyway." Satanael stated. And then he looked at Rias. "But you know what? I am dead boring here and I thought I could entertain myself for the time being. Gremory, I and my generals will volunteer to train your, what was that again? Peerage. What about you two, Apollyon? Sigurd?"

"We have no objections, my lord." They said in unison. Rias was puzzled but still thanked them. Issei didn't get why this Alpha Legion was so feared by that 'grilled chicken', the 'hot maid' and his Buchou. Here came Sigurd and his flashy spectacles for lessoning.

"Do you understand now, Mr. Hyoudou?"

"I… Err… So basically, this Alpha Legion thingy is Kagami's Peerage? And I still don't understand why you guys get those two scared as fuck."

"Because they are the personal guards of the King of Ruin." Rias said, locking eyes with Kagami. "Isn't that correct, Lord Satan?"

"Hah! I expect no less from the sister of the current Lucifer. Even though your power is pitifully weak, I still grant the privilege to be trained by me and my Legion."

Rias' Peerage didn't recover from their shock as Sigurd. made a good point at telling them to keep a secret as Satan, despite his return during the Civil War, hadn't revealed himself truly to the worlds. Apollyon was checking the status of each member of the Peerage and measured their abilities.

"My lord, they consist of two magic users, a melee and agile fighter, a mix of both and a questionable between two." He pointed at Issei, who was then shut up by his stare. Kagami rested his chin on his folded hands and thought.

"Call for Julius, he can teach the nekomata, and Cerberius. I hope the latter can whip something into that pervert." And then he stood up. "Gentlemen, we leave now. Make sure you get the proper equipment, Gremory, as I and my generals are strict instructors. I don't like it when I put my time and effort into something that turns out to be a waste, not at all."

* * *

Satan and his Legion will still be part of the canon plot but they mostly stay in the sideline and handle the other matters such as the Khaos Brigade. And yes, I use a lot of Warhammer 40k's elements in this fics.


End file.
